Radial Ships Space Heater 500 Module

Radial Engineering has shipped its Space Heater 500 single-wide tube overdrive module. The unit is intended to provide natural crunch to drums, adds character to voice, and natural compression to bass and acoustic guitar.

According to Radial’s Jay Porter, "When we launched the eight channel Space Heater, it became immediately apparent that we had no choice but to make a module for our growing 500 series customer base. The Space Heater sounds huge and brings so much excitement to production, it will likely become one of those tools that you use each and every time you lay down a track."

The design begins with a single-wide 500 series module in a fully enclosed steel enclosure to protect its electronics and prevent outside radiation from causing noise—or from the Space Heater 500 creating buzz, due to the high voltage required by the 12AX7 tube.

A 3-position HEAT switch enables the user to choose between 35 volts, 70 volts or 140 volts for the desired level of tube distortion. Distortion is further adjusted using the combination of a drive control plus a level for make-up gain. The plate voltage is generated by an internal charge pump while the Workhorse or 500 series 16V supply provides the 12AX7 tube the 12 volts needed for the heater. A Jensen transformer is employed at the output to bring a more vintage character to the signal path while benefiting from galvanic isolation to reduce hum and buzz caused by ground loops.

The Space Heater 500 is equipped with both high-pass and low-pass filters. These allow the engineer to focus the tube effect on a particular frequency band or spread it out as needed. The EQ can also be applied to the signal path either pre or post tube.

The Space Heater 500 employs a high voltage tube circuit with a current draw of 235 milliamps, so a special power allocation switch adjacent to the card edge connector is available to balance the draw for use with most 500 series racks.